1. Field of the Invention
The present invention relates to tools with jaws and, more particularly, to a hydraulic spike puller.
2. Prior Art
Racine, a division of Framatome Connectors USA, Inc. sells a hydraulic spike puller under the catalog No. HSP-1. A curved jaw surface allows spikes to wedge between the jaw surface and the chute. Such wedging destroys the chute. Jaws must be at the end of the pull stroke to release the spike from the jaws. When the jaws are at the end of the pull stroke, linkage bumpers force the jaws open. The disadvantage to such a mechanism is that the operator must wait for the tool to fully cycle, release the spike and then reposition the tool for the next pull. Jaws close at a down home position as a result of gravity. To grab a spike the jaws must be forced open. Forcing the jaws open is accomplished by slamming the tool and jaws down onto the spike. As a result, jaws are often damaged. In addition such action fatigues the operator. Jaws may not close fully on the spike prior to pull stroke movement. The closing action of the jaw is dependent on the weight of the jaws. If the jaws do not close freely then the spike is difficult to grab and will not be extracted. A chute with an open window design also has a pinch point. Stanley sells a hydraulic spike puller under the designation SP45100A and SP45101A. Stanley also sells an upgrade kit (No. 28647) to convert the SP45100A and SP45101A to SP45100B and SP45101B model hydraulic spike pullers having spring biased members extending from the pivot pin of the jaws.